#include <stdio.h>
#include <mpi.h>
#include "hdfs.h" 

int main(int argc, char **argv) {

    if (argc != 4) {
        fprintf(stderr, "Usage: hdfs_write <filename> <filesize> <buffersize>\n");
        exit(-1);
    }
    
    hdfsFS fs = hdfsConnect("default", 0);
    if (!fs) {
        fprintf(stderr, "Oops! Failed to connect to hdfs!\n");
        exit(-1);
    } 

	clock_t t_start, t_end; 
    int rank, size;
    MPI_Init (&argc, &argv);	
    MPI_Comm_rank (MPI_COMM_WORLD, &rank);	
    MPI_Comm_size (MPI_COMM_WORLD, &size);	

    char* FileName = argv[1];
	
    char writeFileName[80];
    sprintf(writeFileName, "%s%d\n", FileName, rank);
	
    tSize fileTotalSize = strtoul(argv[2], NULL, 10);
    tSize bufferSize = strtoul(argv[3], NULL, 10);
 	
	t_start = clock();
	double profile_time = MPI_Wtime();

    hdfsFile writeFile = hdfsOpenFile(fs, writeFileName, O_WRONLY, bufferSize, 0, 0);
    if (!writeFile) {
        fprintf(stderr, "Failed to open %s for writing!\n", writeFileName);
        exit(-2);
    }

    // data to be written to the file
    char* buffer = malloc(sizeof(char) * bufferSize);
    if(buffer == NULL) {
        return -2;
    }
    int i = 0;
    for (i=0; i < bufferSize; ++i) {
        buffer[i] = 'a' + (i%26);
    }
    
    // write to the file
    tSize nrRemaining;
    for (nrRemaining = fileTotalSize; nrRemaining > 0; nrRemaining -= bufferSize ) {
        int curSize = ( bufferSize < nrRemaining ) ? bufferSize : (int)nrRemaining; 
        hdfsWrite(fs, writeFile, (void*)buffer, curSize); 
    }

    free(buffer);
    hdfsCloseFile(fs, writeFile);

	profile_time = MPI_Wtime() - profile_time;
	t_end = clock();

	printf("%d --- time: %fs %fs\n", rank, profile_time, (double)(t_end - t_start)/(double)CLOCKS_PER_SEC);

    hdfsDisconnect(fs);
	
	MPI_Finalize();
    
	return 0;
}